Apologies, forgot to ask about UV. Any suggestions for this style light? I use UV T8 bulbs for final 3 weeks flower and incorporate into lighting from clone to finish in steps to not harm, but slightly stress. Open to thoughts… was thinking two (2) 10w or 20w would work???

I try to think of it as similar to a 10W white LED. A couple 10W white LEDs can illuminate a room. It’s the close to the same number of photons coming out of the 10W far red LED. The light will not look nearly as bright, however, to the human eye because far red is nearing the limit of visible light and the human eye isn’t as sensitive to red as it is green/yellow.